1. Field of the Invention
This invention relates to an automotive rear view mirror, and more particularly relates to a cleaning apparatus for removing foreign substances from a surface of the mirror.
2. Description of the Related Art
Japanese utility model laid open patent No. 59-40145 published on Mar. 14, 1984 and Japanese utility model laid open patent No. 61-30552 published on Feb. 24, 1986 disclose the cleaning apparatus for an automotive rear view mirror.
FIG. 17 is a perspective view of the cleaning apparatus disclosed in the laid open patent No. 59-40145. Therein, a planer heater 82 is adhered to a back side of a mirror 81. The heater 82 has a pair of electrodes 83, 84. The mirror 81 is heated by the heater 82 when electric power is supplied to the electrodes 83, 84. When the mirror 81 is heated to a pre-determined temperature, water droplets are evaporated and removed from the surface of the mirror 81.
FIG. 16 is a cross sectional view of the cleaning apparatus disclosed in the laid open patent No. 61-30552. Therein, a mirror 71 is supported by a frame 72. The frame 72 is supported by a support 73. A piezoelectric vibrator 74 is interconnected between the frame 72 and the support 73. The piezoelectric vibrator 74 is connected to a driving circuit 76. A power switch 75, which is located in the vehicle (not shown), is interconnected between the driving circuit 76 and a battery 77. While the switch 75 is turned on, the mirror 71 is oscillated by the vibrator 74. When the mirror 71 is vibrated, water droplets are atomized and are removed from the surface of the mirror 71.
However, the cleaning apparatus utilizing the heater arrangement 82 takes a long time for removing the water droplets, due to the length of time required to heat the mirror 71 sufficiently.
Further, the other cleaning apparatus utilizing the vibrator 74 takes a long time for removing ice and frost, because the vibrator 74 cannot heat the mirror 71 to a large degree.